PSTN trunk settings reference

This reference describes the fields available when creating or editing an inbound PSTN trunk. The settings are grouped by the tabs shown in the DIDWW User Panel.

For configuration steps, see Create a PSTN trunk or Manage PSTN trunks.

General

The General tab identifies the trunk, defines its PSTN destination, and controls call capacity and ringing timeout.

Field	Availability	Description
Name	Required	Unique name used to identify the trunk in the DIDWW User Panel.
PSTN Phone Number	Required	Destination to which DIDWW forwards calls. Enter the country code, area code, and subscriber number in E.164 format without +. For example, 12065550100. The destination must be available for PSTN termination.
Capacity Limit	Optional	Maximum number of simultaneous calls that DIDWW can deliver through the trunk. This can restrict, but cannot increase, the Capacity assigned to a DID number. When the limit is reached, DIDWW attempts another trunk in the same Trunk Group when available. If no other trunk is available, the call is rejected and appears in Inbound Call Logs with the response 480 Capacity limit for trunk exceeded. Enter a value from 1 to 32767. The default value is Unlimited.
Ringing Timeout	Optional	Time DIDWW waits for 200 OK after an 18x response. When the timeout is exceeded, the routing attempt ends with the Ringing timeout disconnect code. Enter a value from 1 to 32 seconds.

Use Check Rate to confirm that the destination is available and display its current per-minute rate. Rates vary by destination. See DIDWW pricelists.

Number Translations

The Number Translations tab filters incoming calls by caller ID.

Field	Availability	Description
CLI Number List	Optional	Number List used to allow or reject calls by full-number match, prefix match, or length.

Trunk Group

This optional tab places the trunk in one Trunk Group for failover or load balancing.

Field	Availability	Description
Trunk Group	Optional	Group to which the trunk belongs. A trunk can belong to only one group.
Priority	Trunk Group selected	Attempt order. Lower values are attempted first. Trunks with the same priority are selected according to Weight. Enter a value from 0 to 65535. The default value is 1.
Weight	Trunk Group selected	Relative selection weight among trunks with the same priority. Higher values increase selection likelihood. Enter a value from 0 to 65535. The default value is 65535. See RFC 2782.

Related resources

• Create a PSTN trunk — Create a trunk and configure the settings described on this page.

• Manage PSTN trunks — View, edit, or delete an existing trunk.

• PSTN trunks — Understand how DIDWW forwards inbound calls to PSTN destinations.

• Assign a voice trunk — Assign the trunk to one or more DID numbers.

• Trunk Groups — Configure failover and load balancing across multiple trunks.